Various magnetic disks are available in the market currently for recording and/or reproducing data by means of a flexible disk, a hard disk or a magnetic tape with a magnetic layer coated on the surface thereof or formed as a thin film thereon. Efforts are being made for further development of the device.
These recorder/reproducers include a number of sliding parts which constantly or temporarily slide over and contact with the recording medium. Taking a few examples, there are a magnetic head, a stabilizer for head sliders, and a liner for jacket for flexible disks, a magnetic head, a head slider, guide pins, guide rollers, cylinders, a friction sheet in a cassette for magnetic tapes, and a flying head slider for a hard disk. These sliding parts must be durable, and should not inflict damages on the recording media when they slide over them.
Since there is a necessity to keep a delicate spacing (interval) from the recording medium at the time of recording/reproducing, these magnetic heads and sliders need due care in manufacture, and the material and shape thereof need to be carefully selected. The materials developed for the head slider in the prior art are calcium titanate, barium titanate, hard glass, alumina ceramics, carbon ceramics, etc.
Responding to the recent demand for higher densification in devices, flexible magnetic disks have increased in recording density and minimized in size. Various efforts were made for smaller size and larger capacity in the disks; forming the magnetic layer with thin metal films, increasing the number of revolution of the disk from 300 rpm to 4000 rpm, introducing a servo system for increasing precisions in tracking as observed in hard disks, or decreasing the thickness of a magnetic layer.
In the case of magnetic tapes, digital recording or recording at higher density has been increasingly preferred. Against that background, the defects caused by deviation in running or problems related to sliding have received much attention recently.
Flexible magnetic disks are defective in that the spacing (interval) between a magnetic head and a medium is not stabilized enough to cope with the trend of higher density and higher speed, and an improvement is required. There has been proposed as a solution a method to press the medium from the rear surface, but the method is defective in respect of materials; the materials are not quite wear resistant for use with a novel metal medium or too wear resistant and damages the medium.
Magnetic tapes are defective in respect of the material of guide pins which secure the stable running of the tapes without deviation. The material is required to have a slidability.
The materials should meet stringent requirements in relation to winding and running of tapes in a cassette and should not damage the medium on one hand, and should not be easily damaged by the medium on the other hand.
For hard disk devices, a new system is sought which optimally contacts a magnetic head with a recording medium in order to cope with harsher demands for smaller-size and higher-density systems as well as for a lower flying head.